Never had this one before.. 02 Blazer, Scanned for codes and I have o2 bank1 & bank2 showing up..
Now, this has been going for about a month. Check engine goes on and in a day or two will go off. It cant decide what it wants to do.. Last summer I have changed my o2 bank2 that showed up, but I really dont think that this is a o2 problem here. I was told to clean my MAF that I did, but it would still do the same thing. And also I was told that it could be a fuel filter problem, I will do that in couple of days. I think it is still the original one too...
Has anyone gone thrue this before? Any other ideas incase it is not a filter issue?

 

What are the exact codes (Pxxxx) that are being reported? Diagnosis starts with the code and goes from there. Check out the OBD2 Code Index link in my signature below for some diagnostic procedures that have been posted.

 

It figures... My check engine light is off now.. And never wrote down the exact codes... I will let ya know as soon as it kicks on again..
Thanks

 

The codes are still there. It stores them for a certian amount of drive cycles. The check engine light only comes on when the conditons exist that trigger the code. If the ECM doesnt see those conditions anymore it turns the light off. BUT the ECM has a better memory than a 4 year old that remembers you promised him ice cream! Hook a scanner up and I bet you an ice cream cone you get what youre looking for.

 

Ok.. There back.. P0171 (Bank1) & P0174 (Bank2).. Any Ideas why its doin this?

 

P0171 - Fuel Trim System Lean Bank 1
P0174 - Fuel Trim System Lean Bank 2

Are there any vacuum or exhaust leaks?

 

I have also seen a plugged fuel filter cause this
(Believe it or not)

 

Dont know, havent really had the chance to start lookn around yet. Got my fuel filter couple of days ago, a will start off with that as soon as I have a chance and take it from there.